TO ozone layer recoverythat protects planet Earth from ultraviolet radiation, has been celebrated as one of the greatest environmental achievementsBut in a new study, published Tuesday, some scientists say that Not only may it not be healing, but the hole may even be getting larger. This conclusion comes like this. contradicts previous evaluations on the state of the ozone layer, including a recent UN-supported study that showed it would return to 1980s levels by 2040.
In 1987, several countries agreed to ban or gradually reduce the use of more than a hundred chemicals that degraded the ozone layer and had caused a “hole” in the layer over Antarctica. A degradation that is attributed, above all, to the use of chlorofluorocarbons, common in aerosols, solvents and refrigerants.
TO prohibition of the use of these substancesagreed in the Montreal Protocol, was considered effective in the recovery of the ozone layer, but the hole, which grows in Antarctica during the spring and shrinks again in the summer, reached new highs between 2020 and 2022which led New Zealand scientists investigating the reason. In a paper published in the journal Nature Communications, researchers found that Ozone levels have decreased by 26% since 2004. in the center of the hole.
“This means that the hole not only remained in a large area but also became deeper [com menos ozono] during most of the Antarctic spring. The especially long-lasting ozone holes between 2020 and 2022 fit perfectly into this picture, as the size and depth of the hole during October were particularly notable in all three years,” explained Hannah Kessenich, PhD student at the University of Otago and author of the study, to CNN International.
To reach this conclusion, Scientists analyzed the behavior of the ozone layer. between September and November using satellite information. They used historical data to compare this behavior, the change in ozone levels and measure signs of ozone recovery. They then sought to identify what was causing these changes.
Ultimately, they discovered that the ozone destruction and deepening of the hole were due to changes in the Antarctic polar vortex, a huge swirl of low pressure and very cold air above the South Pole.
The researchers did not study in depth the causes of these changesbut recognized that there are many factors that can also contribute to the ozone destructionincluding the Pollution that warms the planet.toward Small particles emitted by fires and volcanoes. and the Changes in the solar cycle.
“Taken together, our findings reveal that recent large ozone holes may not be caused by CFCs alone. Thus, while the Montreal Protocol has been unquestionably successful in reducing CFCs over time and preventing natural catastrophes, “The recent persistent ozone holes in Antarctica appear to be closely related to changes in atmospheric dynamics,” Kessenich added.
Source: TSF
